Connection Phase Identification System

Abstract

To provide a technology with which, even when an abnormal value is included in a sensor's measurement result, it is possible to estimate the state of a system with high accuracy.SOLUTION: Provided is a connection phase determination system for executing: a calculation process of changing a transformer whose phase type has been specified to assume a plurality of connection states of the transformer, and calculating, for each phase of a power distribution system with respect to the plurality of these assumed connection states, a first difference between a first current in each phase of the power distribution system based on measurement values by a sensor and a second current in each phase of the power distribution system based on measured values by a voltmeter; a setting process of setting an objective function, the evaluation value of which progressively increases as a first difference in each of calculated phases decreases; and a determination process of determining a connection state, the evaluation value of which is maximized, as the connection phase of the transformer. The objective function is such that, when the measured values by the sensor include an outlier, the effect of the outlier in the evaluation value is reduced to be smaller than the effect of measured values other than the outlier.SELECTED DRAWING: Figure 7

Description

[Technical Field] 【0001】 This invention relates to a connection phase determination system. [Background technology] 【0002】 One technique for estimating the connection phase of a pole-mounted transformer to a power distribution system is described in Non-Patent Document 1, for example. [Prior art documents] [Patent Documents] 【0003】 [Non-Patent Document 1] Shunsuke Kono, Yasuhiro Hayashi, Tomihiro Takano, Nobuhiko Itaya, "Basic Research on Phase Estimation of Pole-Mounted Transformers Using Sensor-Integrated Switches and Smart Meter Acquired Information," Proceedings of the 2016 Institute of Electrical Engineers of Japan, Power and Energy Division Conference, 3-1-21~3-1-22 [Overview of the project] [Problems that the invention aims to solve] 【0004】 Incidentally, the technology described in Non-Patent Document 1 uses measurement results from sensors installed in the system. Therefore, for example, if a sensor malfunctions and the measurement results from the sensor include abnormal values ​​(or outliers), it may not be possible to accurately estimate the connected phase. 【0005】 The present invention has been made in view of the above-mentioned conventional problems, and aims to provide a technology that can estimate the connected phase of a pole-mounted transformer with high accuracy, even when abnormal values ​​are included in the measurement results of the sensor. [Means for solving the problem] 【0006】 The present invention, which solves the aforementioned problems, is a connection phase determination system comprising: a transformer connected to each phase of a power distribution system; a sensor that measures at least the voltage and current of the power distribution system; a power meter with a communication function that measures the amount of power supplied from the transformer to the consumer; and a connection phase determination device that determines the connection phase of the transformer to the power distribution system using the measured values ​​from the sensor and information from the power meter with a communication function, wherein the connection phase determination device determines the connection phase of the transformer using the current of each phase of the power distribution system included in the measured values ​​from the sensor and the measured values ​​from the power meter with a communication function, and assumes multiple connection states of the transformer by changing the connection phase of the transformer whose phase type has been specified. A connection phase determination system comprising: a calculation process for each phase of the distribution system, for each of these assumed connection states, calculating a first difference between a first current of each phase of the distribution system based on the measurement value by the sensor and a second current of each phase of the distribution system based on the measurement value by the energy meter; a setting process for setting an objective function such that the evaluation value increases as the first difference for each of the calculated phases decreases; and a determination process for determining the connection state that maximizes the evaluation value as the connected phase of the transformer, wherein the objective function is a function that, when an outlier is included in the measurement value by the sensor, reduces the influence of the outlier in the evaluation value to the influence of the measurement value other than the outlier. [Effects of the Invention] 【0007】 According to the present invention, it is possible to provide a technology that can estimate the connected phase of a pole-mounted transformer with high accuracy, even when abnormal values ​​are included in the measurement results of the sensor. [Brief explanation of the drawing] 【0008】 [Figure 1] This diagram shows the configuration of the connection phase determination system 10. [Figure 2] This diagram illustrates the database and functional blocks of the connection phase determination device 30. [Figure 3] This diagram illustrates the measurement data 70 stored in the sensor measurement value DB50. [Figure 4] It is a diagram for explaining the master data 71 stored in the smart meter information DB 51. [Figure 5] It is a diagram for explaining the measurement data 72 stored in the smart meter information DB 51. [Figure 6] It is a diagram for explaining the current calculated based on the power of the smart meter. [Figure 7] It is a flowchart showing an example of the process S10 executed by the connection phase discrimination device 30. [Figure 8] It is a diagram for explaining the database and functional blocks of the connection phase discrimination device 31. [Figure 9] It is a flowchart showing an example of the process S11 executed by the connection phase discrimination device 31. [Figure 10] It is a diagram for explaining the database and functional blocks of the connection phase discrimination device 35. [Figure 11] It is a flowchart showing an example of the process S15 executed by the connection phase discrimination device 35. [Figure 12] It is a flowchart for explaining the details of the process S40. [Figure 13] It is a diagram showing an example of the values of the difference h1(X) and the correntropy f1(X) for each different connection phase. [Figure 14] It is a diagram showing the relationship between the difference h1(X) and the correntropy f1(X). [Figure 15] It is a diagram for explaining the database and functional blocks of the connection phase discrimination device 36. [Figure 16] It is a flowchart for explaining the details of the process S41. [Figure 17] It is a diagram for explaining the database and functional blocks of the connection phase discrimination device 37. [Figure 18] It is a flowchart showing an example of the process S16 executed by the connection phase discrimination device 37. [Figure 19] It is a diagram showing an example of the discrimination result and the evaluation value for each different kernel size. [Modes for carrying out the invention] 【0009】 The following will become clear from this specification and the accompanying drawings. In this embodiment, blocks and processes denoted by the same reference numerals are the same, and therefore detailed descriptions will be omitted as appropriate. 【0010】 =====Execution===== <<<Configuration of the connection phase determination system 10>>> Figure 1 shows the configuration of a connection phase discrimination system 10, which is one embodiment of the present invention. The connection phase discrimination system 10 is a system that discriminates the connection phase of transformers (described later) connected to three-phase distribution lines 21u to 21w of a power distribution system 20, and includes a switch SE1, pole-mounted transformers TR1 to TR3, smart meters SM1 to SM4, and a connection phase discrimination device 30. 【0011】 Switch SE1 is a sensor-equipped switch that includes sensors for measuring the voltage, current, power factor, etc., of each of the three phase distribution lines 21u to 21w (hereinafter referred to as "each phase" as appropriate). Switch SE1 also transmits the measured values ​​of voltage, etc., measured by the sensors to the connection phase discrimination device 30, which will be described later, via a communication line (not shown). 【0012】 Pole-mounted transformers TR1 to TR3 are distribution transformers connected to each phase located downstream (on the consumer side) of switchgear SE1. The primary sides of pole-mounted transformers TR1, TR2, and TR3 are connected to each phase of the distribution system 20. Here, pole-mounted transformers TR1 and TR2 are shown as single-phase transformers, and pole-mounted transformer TR3 is shown as a three-phase transformer, but the number of pole-mounted transformers and the individual phase types are not limited to the examples shown. 【0013】 Smart meters SM1 to SM4 are connected to the secondary side of pole-mounted transformers TR1, TR2, and TR3, and are communication-enabled electricity meters that measure the amount of electricity used, supply voltage, and current of the customer (not shown). Smart meters SM1 to SM4 measure the above-mentioned amount of electricity used, etc., for example every 30 minutes, and transmit the measured values ​​to the connection phase discrimination device 30. In this embodiment, smart meter SM1 is connected to pole-mounted transformer TR1, smart meters SM2 and SM3 are connected to pole-mounted transformer TR2, and smart meter SM4 is connected to pole-mounted transformer TR3. 【0014】 Furthermore, as will be explained in more detail later, each of the smart meters SM1 to SM4 transmits various information to the connection phase discrimination device 30, in addition to the measured values ​​measured by the smart meters SM1 to SM4, such as the model number and rated voltage of the smart meter SM1 to SM4. 【0015】 ==Phase determination device 30 (first embodiment)== The connection phase determination device 30 is a device that determines the connection phase of the pole-mounted transformer connected to each phase based on the voltage measured by the switch SE1, and the measured values ​​and various information from smart meters SM1 to SM4. The connection phase determination device 30 is a computer that includes a CPU (Central Processing Unit) 40, memory 41, storage device 42, input device 43, display device 44, and communication device 45. 【0016】 The CPU 40 executes programs stored in the memory 41 and the storage device 42 to realize various functions in the connection phase determination device 30. 【0017】 Memory 41 is, for example, RAM (Random-Access Memory) and is used as a temporary storage area for programs, data, etc. 【0018】 The storage device 42 is a non-volatile storage device that stores various data executed or processed by the CPU 40. 【0019】 The input device 43 is a device that accepts commands and data input from the user, and includes input interfaces such as a keyboard and a touch sensor that detects the touch position on a touch panel display. 【0020】 The display device 44 is, for example, a display, and the communication device 45 exchanges various programs and data with other computers and devices via a network (not shown). 【0021】 ==Database and Functional Blocks of the Connection Phase Determination Device 30== Figure 2 shows an example of a database (hereinafter referred to as "DB") stored in the storage device 42 of the connection phase determination device 30, and functional blocks implemented in the connection phase determination device 30. The connection phase determination device 30 includes a sensor measurement value DB 50, a smart meter DB 51, an average value calculation unit 60, a transformer current calculation unit 61, a specification unit 62, a setting unit 63, and a connection phase determination unit 64. Functional blocks such as the average value calculation unit 60 are implemented in the connection phase determination device 30 by the CPU 40 executing a predetermined program. 【0022】 As shown in Figure 3, the sensor measurement value DB50 stores measurement data 70, including the measurement date and time, line voltages, currents for each phase, power factor, etc., based on the measurement values ​​transmitted from the switch SE1. 【0023】 As shown in Figure 4, the smart meter DB51 stores master data 71 related to the pole-mounted transformers to which smart meters SM1 to SM4 are connected, including information on the transformer, its type (including single-phase / three-phase identification information), and its rated voltage. Furthermore, as shown in Figure 5, the smart meter DB51 stores measurement data 72 that is measured and transmitted every 30 minutes by smart meters SM1 to SM4. 【0024】 ==Average value calculation section 60== The average value calculation unit 60 calculates the average active current for a predetermined time cross-section (for example, 30 minutes) at the sensor. Specifically, the average value calculation unit 60 uses the measurement data 70 measured by the sensor to calculate the 30-minute average active currents Iu1, Iv1, and Iw1 for each phase of the power distribution system 20, as shown in Figure 6. Figure 6 shows an example of current measurement for each part of the power distribution system 20. 【0025】 Here, the average active currents Iu1, Iv1, and Iw1 are obtained by multiplying the 30-minute average current measured by the sensor-equipped switch SE1 by the 30-minute average power factor (which is assumed to be 1.0 for convenience). 【0026】 ==Transformer Current Calculation Unit 61== The transformer current calculation unit 61 calculates the average current flowing into the pole-mounted transformers TR1 to TR3 over a predetermined time section (for example, 30 minutes) based on information from the smart meter shown in Figure 6 (measurement data 72, voltage, etc.). For example, suppose that the power consumption over 30 minutes at the smart meter SM1 connected to the pole-mounted transformer TR1 is 750Wh, and the average voltage over 30 minutes is 102V. In such a case, the average current flowing into the pole-mounted transformer TR1 from the distribution system 20 over 30 minutes can be calculated by converting the average current flowing into the smart meter SM1 over 30 minutes to the high-voltage side. 【0027】 Specifically, the average current flowing into the smart meter SM1 over a 30-minute period can be calculated by ((30-minute power consumption / 0.5) / 30-minute average voltage). The 0.5 mentioned above is a coefficient used to convert the power consumption per hour to a 30-minute period. 【0028】 As a result, the average current flowing into the smart meter SM1 over 30 minutes is 750[Wh] / 0.5 / 102[V]=14.7[A]. In this embodiment, the 30-minute average voltage is calculated based on the voltage measured by the smart meter SM1, but for example, a value estimated based on the measured voltage of the switch SE1 and the system impedance (for example, a predetermined impedance) may also be used. Also, here, the 30-minute average power factor is assumed to be 1.0. 【0029】 Furthermore, the average current flowing into the pole-mounted transformer TR1 can be calculated by multiplying the average current flowing into the smart meter SM1 by the transformation ratio. Here, since the transformation ratio is 100 / 6600, the average current flowing into the pole-mounted transformer TR1 over 30 minutes is 14.7[A] × (100 / 6600) = 0.22[A]. 【0030】 Similarly, calculating for pole-mounted transformer TR2, the 30-minute average current flowing into smart meters SM2 and SM3 is 16[A] and 12[A], respectively. Converting this total of 28[A] to the high-voltage side gives 0.42[A]. 【0031】 Since pole-mounted transformer TR3 is a three-phase transformer, the 30-minute average current flowing into smart meter SM4 is 1143[Wh] / 0.5 / (√3×200[V]) = 6.6[A]. Converting this to the high-voltage side, the current flowing into pole-mounted transformer TR3 is 6.6[A] × transformation ratio = 6.6[A] × (200 / 6600) = 0.2[A]. 【0032】 Thus, based on information from the smart meter, the transformer current calculation unit 61 calculates the average current (0.22A, 0.42A, 0.2A) flowing into the pole-mounted transformers TR1 to TR3 over a predetermined time cross-section (for example, 30 minutes), as shown in Figure 6. 【0033】 ==Specific part 62== The identification unit 62 identifies the type (single-phase or three-phase) of pole-mounted transformers TR1 to TR3 based on master data 71, which includes the model numbers (including single-phase / three-phase identification information) and rated voltages of the smart meters SM1 to SM4 shown in Figure 4. In this embodiment, the identification unit 62 identifies that pole-mounted transformers TR1 and TR2 are single-phase, and pole-mounted transformer TR3 is three-phase. 【0034】 ==Settings Section 63== The setting unit 63 sets (formulates) an objective function using corenttropy, as shown in equation (1) below, where X is the combination of connected phases of the pole-mounted transformer. 【number】 【0035】 Here, t is a time segment (e.g., 30 minutes), and T is the number of time segments (in this case, 1). Also, s is the symmetric sensor (in this case, switch SE1), and M is the number of sensors (in this case, 1). 【0036】 Furthermore, p is one of the symmetrical phases u~w, and K is the number of phases (3 in this case). Also, σ is the kernel size (or standard deviation), and I m In the time cross-section t, the measured value of the p-phase current of sensor s, I c This is the calculated value of the p-phase current of sensor s, calculated using the combination of connected phases X and Pt,n at time cross-section t. 【0037】 In Pt,n, n represents the transformer being evaluated, which in this case refers to pole-mounted transformers TR1 and TR2. Furthermore, Pt,n represents the power measured by a communication-enabled electricity meter that measures the amount of power supplied from transformer n to the consumer at time point t. 【0038】 In this embodiment, I m For this purpose, the 30-minute average active currents Iu0, Iv0, and Iw0 calculated by the average value calculation unit 60 are used as the p-phase current (where p is one of u to w) of the switch SE1. In addition, the setting unit 63 sets the current I of each phase in the sensor of the switch SE1 based on the combination of connection phases X of the pole-mounted transformers TR1 and TR2, the power of the smart meters SM1 to SM3, and the power of the smart meter SM4 connected to the pole-mounted transformer TR3. c Calculate. 【0039】 Specifically, the setting unit 63 changes the combination of the average current flowing into the pole-mounted transformers TR1 to TR3 over a predetermined time cross-section (for example, 30 minutes), calculated by the transformer current calculation unit 61, and the connected phases of the pole-mounted transformers TR1 and TR2, thereby changing the current I of each phase in the switch SE1. cCalculate it. 【0040】 Note that the setting unit 63 uses the average current calculated by the transformer current calculation unit 61 to calculate the current I of each phase c However, it is not limited to this. For example, the setting unit 63 may calculate the current I using information such as the power, voltage of the smart meter, the distances from the switch SE1 to the pole-mounted transformers TR1 to TR3, and the impedance of the power distribution system. c It may be calculated. 【0041】 Note that the average effective currents Iu1, Iv1, Iw1 corresponding to I m correspond to the "first current". Also, in this embodiment, the currents of the u-phase to w-phase of the current I c are set as Iu2, Iv2, Iw2 (the "second current"). 【0042】 ==Regarding the objective function== In the above formula (1), when the current I obtained based on the power of the smart meter c is far from the current I m which is the 30-minute average value of the actual measurement results, the value of the objective function Obj(X) becomes smaller and approaches "0" (zero). On the other hand, when the current I c approaches the current I m the value of the objective function Obj(X) becomes larger. 【0043】 Here, when the combination X of the connection phases of the pole-mounted transformers matches the actual combination, the current I c and the current I m become almost equal. Therefore, by changing the combination X of the connection phases and identifying the combination when the value of the objective function Obj(X) (hereinafter referred to as the "evaluation value") becomes maximum, the actual combination of the connection phases can be determined. 【0044】 By the way, among the sensors that measure each phase (u~w) of the switch SE1, for example, if one of the sensors for any phase malfunctions, the measurement value of the sensor for any of the phases may output an abnormal value (outlier). However, the objective function Obj(X) in this embodiment uses the corentropy method. In the corentropy method, as described above, the current I c And, current I m The difference between these values ​​is evaluated using the formula for a normal distribution. Therefore, among the measured values, normal values ​​(i.e., values ​​close to the center of the normal distribution) have a large impact, while outlier values ​​(i.e., values ​​far from the center of the normal distribution) have a small impact. 【0045】 Therefore, even if the sensor value for any phase outputs an abnormal value, the influence of the abnormal value on the evaluation value of the objective function Obj(X) can be suppressed. Thus, in this embodiment, the influence of abnormal values ​​can be suppressed when the combination X of connected phases of the pole-mounted transformer is changed. 【0046】 ==Connection Phase Determination Unit 64== The connection phase determination unit 64 determines the connection state that maximizes the evaluation value of the objective function Obj(X) in equation (1) when the combination of connection phases X is changed to be the connection phase of the transformer. Changing the combination of connection phases X means, for example, changing the single-phase type to UV, VW, WU, which is equivalent to "assuming multiple connection states". 【0047】 <<<<Processing S10 executed by the connection phase determination device 30>>>> Figure 7 is a flowchart showing an example of processing S10 performed by the connection phase determination device 30. First, the average value calculation unit 60 uses the measurement data 70 to calculate the average active current at the sensor over a predetermined time cross-section (for example, 30 minutes) (S20). 【0048】 Next, the transformer current calculation unit 61 calculates the average current flowing into the pole-mounted transformers TR1 to TR3 over a predetermined time section (e.g., 30 minutes) based on the measured values ​​from the smart meter (e.g., measurement data 72, voltage, etc.) (S21). Then, the identification unit 62 identifies the type of pole-mounted transformers TR1 to TR3 based on the information from the smart meter (master data 71) (S22). 【0049】 The setting unit 63 then sets (formulates) the objective function Obj(X) in equation (1) described above (S23). The connection phase discrimination unit 64 then determines the connection state that maximizes the evaluation value of the objective function Obj(X) in equation (1) when the combination of connection phases X is changed to be the connection phase of the transformer (S24). The connection phase discrimination unit 64 also displays the discrimination result on the screen of the display device 44 in Figure 1, for example. As a result, the user can understand the connection phase of the pole-mounted transformer connected to each phase of the distribution system 20. Process S23 corresponds to "calculation process" and "setting process", and process S24 corresponds to "discrimination process". 【0050】 <<<<Second Embodiment of the Connection Phase Discrimination Device>>>> Figure 8 shows a second embodiment of the connection phase determination device, the connection phase determination device 31. The connection phase determination device 31 is similar to the connection phase determination device 30 in Figure 1, but some of the functional blocks implemented are different. Specifically, the connection phase determination device 31 includes a sensor measurement value DB50, a smart meter DB51, an average value calculation unit 100, a specification unit 62, a setting unit 101, and a connection phase determination unit 102. Here, the blocks with the same reference numerals in Figure 8 and Figure 2 are the same. For this reason, the average value calculation unit 100, the setting unit 101, and the connection phase determination unit 102 will be described below. 【0051】 ==Average Value Calculation Unit 100== The average value calculation unit 100 calculates the average active current and average voltage of the sensor over a predetermined time cross-section (e.g., 30 minutes). Specifically, the average value calculation unit 60 uses the measurement data 70 measured by the sensor to calculate the current I of each phase as described above. m And the voltage V of each phase m We will find the following for each phase voltage V.m Let Vu1, Vv1, and Vw1 be the average voltages over 30 minutes. 【0052】 ==Settings Section 101== The setting unit 101 performs power flow calculations using measured values ​​from smart meters (for example, measurement data 72 (power value) and voltage, etc.) and a system model that simulates the distribution system 20 represented by a state equation, and calculates the average current I of each phase over 30 minutes at the switch SE1. c And the average voltage V of each phase c The average current I over 30 minutes in switch SE1 is calculated. c This is the same as that calculated by the connection phase determination device 30. Furthermore, the average voltage V of each phase is as follows: c Let Vu2, Vv2, and Vw2 be the average voltages over 30 minutes. 【0053】 Furthermore, the setting unit 101 sets (formulates) an objective function using corenttropy, as shown in equation (2) below, where X is the combination of connected phases of the pole-mounted transformer. 【number】 【0054】 Here, t, T, etc. in equation (2) are the same as in equation (1) above. Also, in equation (1), the current I m And, current I c The objective function is such that the evaluation value increases as the difference with decreases, but equation (2) is given by current I m and current I c The difference (the first difference) and the voltage V m and voltage V c The objective function is such that the evaluation value increases as the difference between (the second difference) and decreases. In other words, equation (2) is an objective function that takes into account not only the difference in current of switch SE1 in the distribution system 20, but also the difference in voltage. Note that the voltage V m This corresponds to the "first voltage," and the voltage V c This corresponds to the "second voltage". 【0055】 ==Connection Phase Determination Unit 102== The connection phase discrimination unit 102 determines the connection state that maximizes the evaluation value of the objective function Obj(X) in equation (2) when the combination of connection phases X is changed to be the connection phase of the transformer. 【0056】 <<<<Processing S11 executed by the connection phase determination device 31>>>> Figure 9 is a flowchart showing an example of processing S11 performed by the connection phase determination device 31. First, the average value calculation unit 100 uses the measurement data 70 to calculate the average active current and average voltage of the sensor over a predetermined time cross-section (for example, 30 minutes) (S30). 【0057】 Next, the identification unit 62 identifies the types of pole-mounted transformers TR1 to TR3 based on information from the smart meter (master data 71) (S31). 【0058】 The setting unit 101 then sets (formulates) the objective function Obj(X) in equation (2) described above (S32). The connection phase determination unit 102 then determines the connection state that maximizes the evaluation value of the objective function Obj(X) in equation (2) when the combination of connection phases X is changed to be the connection phase of the transformer (S33). The connection phase determination unit 102 also displays the determination result on the screen of the display device 44 in Figure 1, for example. As a result, the user can understand the connection phase of the pole-mounted transformer connected to each phase of the power distribution system 20. 【0059】 <<<<Third Embodiment of the Connection Phase Discrimination Device>>>> Figure 10 shows a connection phase determination device 35, which is a third embodiment of the connection phase determination device. The connection phase determination device 35 is similar to the connection phase determination device 30 in Figure 1, but some of the functional blocks implemented are different. Specifically, the connection phase determination device 35 includes a setting unit 65 instead of the setting unit 63 of the connection phase determination device 30 in Figure 1. 【0060】 ==Settings Section 65== The setting unit 65 selects a kernel size σ from several kernel sizes σ that satisfies predetermined conditions described later. Then, the setting unit 65 sets (formulates) an objective function using the colentropy f1(X) with the selected kernel size σ. Details of the setting unit 65, along with the processes it performs, will be described later. 【0061】 <<<<Processing S15 executed by the connection phase determination device 35>>>> Figure 11 is a flowchart showing an example of process S15 performed by the connection phase determination device 35. Since the processes indicated by the same reference numerals in Figure 11 and Figure 7 are the same, in this embodiment, process S40 will be described. Figure 12 is a flowchart showing an example of process S40. Here, we assume the case where the connection phases of pole-mounted transformers TR1 and TR2 shown in Figure 1 are determined. 【0062】 First, the setting unit 65 sets the initial value of the kernel size σ of the corentropy f1(X) shown in equation (1) above (S50). For example, the initial value of the kernel size σ is 0.01. 【0063】 Next, the setting unit 65 uses the set kernel size σ to determine the current I in the numerator of the collentropy f1(X) for each combination X of connected phases. m and current I c The difference (hereinafter, the difference h1(X) = I m -I c Let's assume that...) Then, calculate the corentropy f1(X) and (S51). Note that process S51 corresponds to "process to calculate the value of corentropy". 【0064】 Figure 13 shows the relationship between the connection phase combination X, the difference h1(X), and the correntropy f1(X). As mentioned above, we assume the connection phase combination X for pole-mounted transformers TR1 and TR2. Therefore, the difference h1(X) in Figure 13 and the correntropy f1(X) corresponding to the kernel size σ=0.01 are calculated for each of the multiple combinations X. 【0065】 Figure 14 shows the relationship between the difference h1(X) on the horizontal axis and the correntropy f1(X) on the vertical axis. When the kernel size σ is small, for example, 0.01, the influence of outliers can be suppressed, but depending on the variability, the influence of correct measurements may also become small. Therefore, in this embodiment, the kernel size σ is changed so that the influence of correct measurements is large while the influence of outliers is suppressed, and the correntropy f1(X) is calculated for multiple kernel sizes σ. 【0066】 As shown in Figure 12, the setting unit 65 determines whether the kernel size σ has been changed up to a predetermined kernel size σ (S52). For example, in this embodiment, the kernel size σ is changed from the initial value of 0.01 to 0.02, and then to 0.04. 【0067】 Therefore, if the kernel size σ has not been changed (S52: No), the setting unit 65 changes the kernel size σ (S53). Then, the setting unit 65 executes processes S51 and S52 again. As these processes are repeated, the corentropy f1(X) corresponding to kernel sizes σ=0.02 and 0.04 in Figure 13 is calculated for each of the multiple combinations X (S51). 【0068】 Incidentally, as shown in Figure 14, increasing the kernel size σ from 0.01 to, for example, 0.02 gradually increases the influence of correct measurements, including variability. Furthermore, increasing the kernel size σ from 0.02 to, for example, 0.04 further increases the influence of measurements, including variability, but also increases the influence of outliers. 【0069】 In this way, by changing the kernel size σ, it is possible to calculate a colentropy f1(X) value in which the influence of the correct measurement value and the outlier value differs, as shown in Figure 13. In this embodiment, the colentropy f1(X) value for each of the multiple combinations X shown in Figure 13 is stored in the storage device 42 of the connection phase discrimination device 35. When the kernel size σ is changed to 0.04 and processing S51 is executed, the setting unit 65 determines that the change of kernel size σ has been completed (S52: Yes). 【0070】 Then, the setting unit 65 selects a kernel size (S54) based on the corentropy f1(X) value for each of the multiple kernel sizes σ shown in Figure 13, which is calculated for each of the multiple combinations X. Specifically, the setting unit 65 selects a kernel size such that the number of combinations where the multiple corentropy f1(X) values ​​calculated for each of the multiple kernel sizes σ are less than or equal to a predetermined threshold T1 is N1 or less. Note that process S54 corresponds to the "selection process". 【0071】 In this embodiment, the predetermined threshold T1 is, for example, 5, and N1 is, for example, 0. The predetermined threshold T1 corresponds to the "first threshold," and N1 corresponds to the "first value." 【0072】 As shown in Figure 13, when the kernel size σ is 0.01, there are 5 numbers for which the colentropy f1(X) value is 5 or less. On the other hand, when the kernel size σ is 0.02 or 0.04, there are 0 numbers for which the colentropy f1(X) value is 5 or less. Therefore, the setting unit 65 selects two of the three kernel sizes σ: 0.02 and 0.04. 【0073】 Furthermore, the setting unit 65 of this embodiment selects the smallest kernel size σ, which is 0.02, from among the two kernel sizes σ. 【0074】 When a kernel size σ (here, 0.02) is selected in process S54, the setting unit 65 sets the objective function Obj(X) using the corentropy f1(X) that includes the selected kernel size σ (S55). As a result, process S40 in Figure 11 is completed. 【0075】 Then, the connection phase discrimination device 35 determines the connection state that maximizes the evaluation value of the objective function Obj(X) when the combination of connection phases X is changed to be the connection phase of the transformer (S24). As a result, users can understand the connection phase of the pole-mounted transformers connected to each phase of the distribution system 20. 【0076】 <<<<Fourth Embodiment of the Connection Phase Discrimination Device>>>> Figure 15 shows a connection phase determination device 36, which is a fourth embodiment of the connection phase determination device. The connection phase determination device 36 is similar to the connection phase determination device 31 in Figure 8, but some of the functional blocks implemented are different. Specifically, the connection phase determination device 36 includes a setting unit 110 instead of the setting unit 101 of the connection phase determination device 31 in Figure 8. 【0077】 ==Settings Section 110== The setting unit 110, like the setting unit 101, sets (formulates) the objective function Obj(X) in equation (2) described above. 【0078】 However, when setting the objective function Obj(X), the setting unit 110, like the setting unit 65, sets the current I in equation (2). m and current I c The kernel size σ (hereinafter referred to as kernel size σ1) of the corentropy f1(X) using the difference (first difference), and the voltage V m and voltage V c The kernel size σ (hereinafter referred to as kernel size σ2) of the corentropy f2(X) using the difference (second difference) is selected. 【0079】 <<<<Processing performed by the connection phase determination device 36>>>> When the connection phase determination device 36 determines the connection phase, the setting unit 110 executes process S41 in Figure 16 in process S32 in Figure 9. Figure 16 is a flowchart S41 showing an example of the process in which the setting unit 110 selects kernel sizes σ1 and σ2. 【0080】 Each of the processes S60 to S65 included in process S41 is the same as the processes S50 to S55 included in process S40 in Figure 12. Therefore, when process S41 is executed, the kernel size σ1 of the corentropy f1(X) and the kernel size σ2 of the corentropy f2(X) are selected, and the objective function is set. 【0081】 Furthermore, in processing S64, the setting unit 110 selects a kernel size from multiple kernel sizes σ1 such that the number of multiple corentropy f1(X) values ​​that are less than or equal to a predetermined threshold T1 is N1 or less. In addition, in processing S64, the setting unit 110 selects a kernel size from multiple kernel sizes σ2 such that the number of multiple corentropy f2(X) values ​​that are less than or equal to a predetermined threshold T2 is N2 or less. 【0082】 In this embodiment, the predetermined thresholds T1 and T2 are, for example, 5, and the number of N1 and N2 is, for example, 0. 【0083】 The connection phase determination device 36 then determines the connection state that maximizes the evaluation value of the objective function Obj(X) including the kernel sizes σ1 and σ2 selected in process S41 as the connection phase of the transformer (for example, S33 in Figure 9). As a result, even when using the connection phase determination device 36, users can understand the connection phase of the pole-mounted transformers connected to each phase of the distribution system 20. 【0084】 Note that kernel size σ1 corresponds to the "first kernel size," and corentropy f1(X) corresponds to the "first corentropy." Also, kernel size σ2 corresponds to the "second kernel size," and corentropy f2(X) corresponds to the "second corentropy." 【0085】 A predetermined threshold T1 corresponds to the "first threshold," and N1 values ​​correspond to the "first value." Similarly, a predetermined threshold T2 corresponds to the "second threshold," and N2 values ​​correspond to the "second value." Process S64 corresponds to the "first selection process" and the "second selection process." 【0086】 <<<<Fifth Embodiment of the Connection Phase Discrimination Device>>>> Figure 17 shows a fifth embodiment of the connection phase determination device, the connection phase determination device 37. The connection phase determination device 37 is similar to the connection phase determination device 31 in Figure 8, but some of the functional blocks implemented are different. Specifically, in addition to the functional blocks of the connection phase determination device 31 in Figure 8, the connection phase determination device 37 includes a control unit 200 and a connection phase determination unit 201. 【0087】 ==Control Unit 200== The control unit 200 controls the setting unit 63 and the connection phase discrimination unit 64 for each of the multiple kernel sizes and causes them to execute their respective processes. As will be described in detail later, as a result, for each of the multiple kernel sizes, the discrimination result determined by the connection phase discrimination unit 64 and the evaluation value of the objective function Obj(X) can be obtained. 【0088】 ==Connection Phase Determination Unit 201== The connection phase determination unit 201 determines the connection phase of the pole-mounted transformers connected to each phase of the power distribution system 20 based on the determination results obtained for each of the multiple kernel sizes. 【0089】 <<<<Processing performed by the connection phase determination device 37>>>> Figure 18 is a flowchart showing an example of processing S16 performed by the connection phase determination device 37. Since the processes S20 to S24, which are denoted by the same reference numerals in Figure 18 and Figure 7, are the same, this embodiment will mainly describe processes S100 to S102. Here, the connection phase determination device 37 determines the connection phases of the six pole-mounted transformers TR1 to TR6. Also, the initial value of the kernel size σ is set to, for example, 0.01. 【0090】 In Figure 18, when processes S20 to S24 are executed, the determination results of the connected phases of pole-mounted transformers TR1 to TR6 and the evaluation value of the objective function Obj(X) are obtained, as shown in the row of the table in Figure 19 where the kernel size σ is 0.01. Here, the connected phase determination unit 64 stores the determination results from process S24 and the evaluation value of the objective function Obj(X) in the memory device 42. 【0091】 When the connection phase determination unit 64 executes process S24, the control unit 200 determines whether the kernel size change σ has been completed (S100). Here, the kernel size σ is changed from the initial value (0.01) through 0.02, 0, 04, 0.06, 0.08, and up to 0.10. 【0092】 Therefore, for example, if the kernel size σ is at its initial value (0.01), the control unit 200 determines that the change in kernel size σ is not yet complete (S100: No). Subsequently, the control unit 200 sets the kernel size σ to 0.02 and causes the setting unit 63 and the connection phase determination unit 64 to execute the process S23 for setting the objective function Obj(X) and the connection phase determination process S24 (S23, S24). 【0093】 In this embodiment, once processes S23 and S24 have been executed for all six different kernel sizes σ, the control unit 200 terminates the kernel size change σ (S100: Yes). As a result, as shown in Figure 19, the determination result of the connected phase and the evaluation value of the objective function Obj(X) are obtained for each of the six kernel sizes. 【0094】 The connection phase determination unit 201 determines the connection phases of pole-mounted transformers TR1 to TR6 based on the determination results of the connection phases for each of the six kernel sizes (S102). Specifically, the connection phase determination unit 201 determines the connection phase that is most frequently determined among the determination results of the connection phases for each of the six kernel sizes as the connection phase of the pole-mounted transformer. 【0095】 For example, as shown in Figure 19, in the case of pole-mounted transformer TR1, all six discrimination results are uv. Therefore, the connection phase determination unit 201 determines that the connection phase of pole-mounted transformer TR1 is uv. The same applies to pole-mounted transformers TR2 to TR5. 【0096】 On the other hand, in the case of pole-mounted transformer TR6, four of the six determination results are uv and two are wu. Therefore, in this case, the connection phase determination unit 201 determines that the connection phase of pole-mounted transformer TR6 is uv. As a result, users can more accurately determine the connection phase of the pole-mounted transformers connected to each phase of the distribution system 20. Note that process S102 corresponds to the "determination process". 【0097】 ===Other processing by the connection phase determination unit 201 (sum of evaluation values)=== Here, in processing S102, the connection phase determination unit 201 determined the connection phase that was most frequently identified among the connection phase determination results for each kernel size as the connection phase of the pole-mounted transformer, but is not limited to this. For example, the connection phase determination unit 201 may determine the connection phase based on the connection phase determination results for each kernel size and the evaluation value of the objective function Obj(X). 【0098】 For example, in the pole-mounted transformer TR6 shown in Figure 19, when the kernel size σ is 0.01, 0.06, 0.08, and 0.10, it is determined to be uv, and when the kernel size σ is 0.02 and 0.04, it is determined to be wu. In this case, the connection phase determination unit 201 determines the connection phase with the largest sum of the evaluation values ​​of the determined connection phases as the connection phase of the pole-mounted transformer. 【0099】 Here, the sum of the evaluation values ​​identified as uv is 4200 (=1000+1700+1000+500). On the other hand, the sum of the evaluation values ​​identified as wu is 2900 (=1300+1600). Therefore, the connection phase determination unit 201 determines that the connection phase of pole-mounted transformer TR6 is uv. 【0100】 ===Other processing (weighting coefficients) of the connection phase determination unit 201=== Furthermore, the connection phase determination unit 201 may determine the connection phase based on the determination result of the connection phase for each kernel size, the evaluation value of the objective function Obj(X), and a weighting coefficient that increases as the evaluation value increases. In this embodiment, for example, the weighting coefficients 2.0, 1.5, and 1.2 are assigned to the top three evaluation values ​​in Figure 19. 【0101】 Then, when determining the connection phase of the pole-mounted transformer TR6, the connection phase determination unit 201 multiplies the target evaluation value by a weighting coefficient and calculates the sum of the evaluation values. As a result, the sum of evaluation values ​​determined to be uv is 5900 (=2.0 × 1700 + 1000 + 1000 + 500). On the other hand, the sum of evaluation values ​​determined to be wu is 3960 (=1.5 × 1600 + 1.2 × 1300). The connection phase determination unit 201 then determines that the connection phase of the pole-mounted transformer TR6 is uv, which has a larger sum of evaluation values ​​considering the weighting coefficient. 【0102】 In this way, the connection phase determination unit 201 determines the connection phase not only based on the discrimination result but also on evaluation values ​​and weighting coefficients, allowing users to more accurately understand the connection phase of the pole-mounted transformers connected to each phase of the power distribution system 20. 【0103】 =====Summary===== The connection phase determination devices 30 and 31 of this embodiment have been described above. When the connection phase determination device 30 determines the combination X of connection phases, it uses an objective function in which the influence of abnormal values ​​(or outliers) is smaller than the influence of normal values. Therefore, even if the sensor of the switch SE1 malfunctions, the connection phase of the pole-mounted transformer can be determined with high accuracy. 【0104】 Furthermore, as the objective function, a function using the corentropy method can be used, for example, as shown in equation (1). In this embodiment, the corentropy method using the form of the normal distribution formula is used, but a function that reduces the influence of outliers that deviate from the normal value (for example, a triangular distribution or a Poisson distribution) may also be used. Even when using such a distribution, it is possible to suppress the influence of outliers. 【0105】 Furthermore, the setting unit 65 may, for example, select one of the two kernel sizes σ, 0.02 or 0.04, from the three kernel sizes σ shown in Figure 13. Even in such a case, the user can accurately determine the connected phase of the pole-mounted transformers connected to each phase of the power distribution system 20. 【0106】 Furthermore, the setting unit 65 of this embodiment, for example, in Figure 13, selects the smallest kernel size σ, which is 0.02, from the two kernel sizes σ(0.02, 0.04). Therefore, the user can determine the connected phase of the pole-mounted transformers connected to each phase of the power distribution system 20 with higher accuracy. 【0107】 Furthermore, the connection phase determination device 31 can determine the connection phase of the pole-mounted transformer with greater accuracy by, for example, performing power flow calculations and using the objective function of equation (2) which includes current and voltage. 【0108】 For example, the connection phase determination device 36 may also perform power flow calculations in the same way as the connection phase determination device 31, and use the objective function of equation (2) which includes current and voltage. 【0109】 Alternatively, the connection phase determination device 36 may perform the process S41 shown in Figure 16 to select the kernel size σ1 of the corentropy f1(X) and the kernel size σ2 of the corentropy f2(X), and then set the objective function. Even in this case, the connection phase of the pole-mounted transformers connected to each phase of the power distribution system 20 can be determined with high accuracy. 【0110】 Furthermore, in processing S64, if multiple kernel sizes σ1 and σ2 are selectable, the connection phase determination device 36 should select the smallest kernel size. 【0111】 Furthermore, the connection phase determination unit 201 determines the connection phase of the transformer based on multiple determination results for the connection phase determined for each of the multiple kernel sizes (for example, process S102). As a result, the connection phase of the transformer can be determined with higher accuracy than determination results obtained using only one kernel size. 【0112】 Alternatively, the connection phase determination unit 201 may determine the connection phase that is most frequently identified (in this case, uv) from among the determination results for connection phases for each of the six kernel sizes as the connection phase of the pole-mounted transformer TR6. 【0113】 Alternatively, the connection phase determination unit 201 may determine the connection phase with the largest sum of the evaluation values ​​of the identified connection phases as the connection phase of the pole-mounted transformer. 【0114】 Furthermore, the connection phase determination unit 201 may determine the connection phase not only based on the discrimination result, but also based on evaluation values ​​and weighting coefficients. Even in this case, users can accurately understand the connection phase of the pole-mounted transformers connected to each phase of the distribution system 20. 【0115】 Furthermore, for example, the specific unit 62 can identify the type of pole-mounted transformer based on various information such as the model number and rated voltage of the smart meters SM1 to SM4. 【0116】 The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. Furthermore, the present invention may be modified or improved without departing from its spirit, and it goes without saying that equivalents thereof are included. [Explanation of Symbols] 【0117】 20 Power distribution system 21u~21w distribution line 30, 31, 35, 36 Connection Phase Identification Device 40 CPU 41 memory 42 Storage device 43 Input device 44 Display device 45 Communication equipment 50 Sensor Measurement Value Database 51 Smart Meter DB 60,100 Average value calculation section 61 Transformer Current Calculation Unit 62 Specific part 63, 65, 101, 110 Setting section 64,102 Connection Phase Determination Unit 70,72 Measurement data 71 Master Data 200 Control Unit 201 Connection Phase Determination Unit

Claims

[Claim 1] A connection phase determination system comprising: transformers connected to each phase of a power distribution system; sensors that measure at least the voltage and current of the power distribution system; a power meter with communication function that measures the amount of power supplied from the transformers to consumers; and a connection phase determination device that determines the connection phase of the transformers to the power distribution system using the values ​​measured by the sensors and information from the power meter with communication function, The aforementioned connection phase determination device is The current of each phase of the power distribution system included in the measurement values ​​from the sensor and the measurement values ​​from the power meter with communication function are used to determine the connected phase of the transformer, and multiple connection states of the transformer are assumed by changing the connected phase of the transformer whose phase type has been identified, and for these assumed multiple connection states, A calculation process for each phase of the power distribution system, which calculates the first difference between the first current of each phase of the power distribution system based on the measurement value by the sensor and the second current of each phase of the power distribution system based on the measurement value by the energy meter, A setting process to set an objective function in which the evaluation value increases as the first difference of each of the calculated phases becomes smaller, A determination process that determines the connection state that maximizes the evaluation value as the connected phase of the transformer, Execute, The objective function is a function that, when the measured value from the sensor includes an outlier, reduces the influence of the outlier in the evaluation value to less than the influence of the other measured values. The aforementioned objective function is a function using collentropy, which expresses the first difference using the formula for a normal distribution. Connection phase identification system. [Claim 2] A connection phase determination system according to claim 1, The aforementioned configuration process is: A process for calculating multiple coretropy values ​​based on the first difference between each of the assumed multiple connection states for each of the multiple kernel sizes, A selection process is performed to select a kernel size from the multiple kernel sizes based on the number of coretropy values ​​calculated for each of the multiple kernel sizes that are less than or equal to a first threshold, A process in which the objective function is a function using the coretropy including the selected kernel size, Includes, The kernel size is the standard deviation of the normal distribution. Connection phase identification system. [Claim 3] A connection phase determination system according to claim 2, The aforementioned selection process is, This process involves selecting the smallest kernel size from the plurality of kernel sizes such that the number of values ​​below the first threshold is less than or equal to the first value. Connection phase identification system. [Claim 4] A connection phase determination system according to claim 1, The aforementioned connection phase determination device is The connected phase of the transformer is determined by further using the voltage of each phase of the power distribution system included in the measured value by the sensor, The calculation process described above applies to the multiple connection states, The second difference between the first voltage of each phase of the distribution system based on the measurement value by the sensor and the second voltage of each phase of the distribution system based on the measurement value by the energy meter is calculated for each phase of the distribution system. The aforementioned configuration process is: The objective function is set such that the smaller the difference between the first and second phases of each of the calculated phases, the larger the evaluation value becomes. The aforementioned objective function is a function using collentropy, in which the differences between the first and second are expressed using the formula for a normal distribution. Connection phase identification system. [Claim 5] A connection phase determination system according to claim 4, The aforementioned objective function is, The aforementioned colenttropy is a function that uses a first colenttropy based on the first difference and a second colenttropy based on the second difference. The aforementioned configuration process is: A process for calculating multiple first colentropy values ​​based on the first difference between each of the assumed multiple connection states for each of the multiple first kernel sizes, and multiple second colentropy values ​​based on the second difference between each of the assumed multiple connection states for each of the multiple second kernel sizes, A first selection process for selecting a kernel size from the plurality of first kernel sizes based on the number of first coretropy values ​​calculated for each of the plurality of first kernel sizes that are less than or equal to a first threshold, A second selection process in which a kernel size is selected from the plurality of second kernel sizes based on the number of second coretropy values ​​calculated for each of the plurality of second kernel sizes that are less than or equal to a second threshold, A process in which the objective function is a function using the first colenttropy including the selected kernel size and the second colenttropy including the selected kernel size, Includes, The first kernel size represents the standard deviation of the normal distribution of the first difference, The second kernel size represents the standard deviation of the normal distribution of the second difference. Connection phase identification system. [Claim 6] A connection phase determination system according to claim 5, The first selection process is, Among the first kernel sizes for which the number of values ​​less than or equal to the first threshold is less than or equal to the first value, the smallest first kernel size is selected from the plurality of first kernel sizes. The second selection process described above is: Among the second kernel sizes for which the number of values ​​less than or equal to the second threshold is less than or equal to the second value, the smallest second kernel size is selected from the plurality of second kernel sizes. Connection phase identification system. [Claim 7] A connection phase determination system according to claim 1, The aforementioned connection phase determination device is For each of the multiple kernel sizes, a process is performed to execute the setting process and the determination process. A determination process to determine the connected phase of the transformer based on the multiple determination results of the connected phase of the transformer determined for each of the multiple kernel sizes, Execute, The kernel size is the standard deviation of the normal distribution. Connection phase identification system. [Claim 8] A connection phase determination system according to claim 7, The aforementioned decision process is, Of the multiple determination results mentioned above, the connection phase that was most frequently determined is determined to be the connection phase of the transformer. Connection phase identification system. [Claim 9] A connection phase determination system according to claim 7, The aforementioned decision process is, Based on the plurality of discrimination results and the evaluation values ​​for each of the plurality of kernel sizes, the connected phase of the transformer is determined. Connection phase identification system. [Claim 10] A connection phase determination system according to claim 9, The aforementioned decision process is, Based on the plurality of discrimination results, the evaluation values ​​for each of the plurality of kernel sizes, and a weighting coefficient that increases as the evaluation value increases, the connected phase of the transformer is determined. Connection phase identification system. [Claim 11] A connection phase determination system according to any one of claims 1 to 10, The information from the aforementioned energy meter with communication function includes at least one of the following: the measured voltage of the energy meter with communication function, the model of the energy meter with communication function, and the rated voltage of the energy meter with communication function. The connection phase determination device performs a process to identify the phase type of the transformer based on information from the electricity meter with communication function. Connection phase identification system.

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